Abstract: A perpetual calendar device as set forth which continually maintains a display of the present month and day as well as the minimum birth year for an individual who is entitled to purchase alcohol or tobacco products. The displays of the birth year information can be switched back and forth between the alcohol birth year display and the tobacco birth year display as desired to prevent confusion by the clerk. The displays are identified. The device is adapted for use by store clerks and the like to check to determine whether an individual wishing to purchase these products has attained the minimum age required.